Automatically-movable dam-crest.



PATENTED FEB. 5, 1,907.

A W. R. DAVIS. AUTOMATICALLY MOVABLE DAM CREST.

APPLIOATION FILED N0 V.16,1906.

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No. 843,003. PATENTED PEB= 5, 1907. W. R. DAVIS.

AUTOMATICALLY MOVABLE DAM CREST.

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w. R. DAVIS.

AUTOMATICALLY MOVABLE DAM'CREST.

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PATENTED FEB. 5, 1907. w. R. DAVIS.

AUTOMATICALLY MOVABLE DAM-CREST.

APPLICATION FILED NOV. 16, 1906.

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WILLIAM R. DAVIS, OF ALBANY, NEW YORK.

AUTOMATICALLY-MOVABLE DAM-CREST.

Specification of Letters Patent.

Patented Feb. 5, 1907.

. Application filed November 16, 1906. Serial No. 343,735.

To all 1,071,017?) it may concern:

Be it known that I, WILLIAM RUssELL DA- v1s, a citizen of the UnitedStates, residing at Albany, in the county of Albany and State of NewYork, have invented certain new and useful Improvements inAutomatically- Movable Dam-Crests; and I do hereby declare the followingto be a full, clear, act description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, and toletters or figures of reference marked thereon, which form a part ofthis specification.

My invention relates to a movable damcrest to control the pool above thedam in accordance with the rise of level thereof, due to the varyingsupply and varying conditions of use; and my invention has for itsobject a movable dam-crest automatically operated by the rise in levelexcess of water to flow from the pool, with details of construction tobe hereinafter referred to and claimed. 9

Referring to the drawings, in which like parts are similarly designated,Figure 1 is a side view of the dam-crest. Fig. 2 is a section throughthe fixed counterweight-box and showing the supporting-arm in section.Flg. 3 is an end view of Fig. 1 looking in the direction of the arrow.Fig. 4 is a view similar to Fig. 1 showing a swinging counterweight.Fig. 5 is a plan view of Fig. 4.

Referring now to Figs. 1 to 3, the top of the dam 1 is flanked by sidewalls 2, preferably built of masonry, concrete, wood, or the like, aslocal conditions may require or demand. In each of the side walls 2there is a bearing 3 for the ends of shaft 4, or it may be that the endsof the shaft 4 are rigidly secured in the side walls, the height of thisdam 1 being but not necessarily, at about the normal water-level h ofthe pool. The damcrest is mounted to rotate about shaft 4 and normallyrests on the top of the dam 1. The

sides of the dam-crest are shown constructed of sheet-metal side walls5. However, I do not limit myself to this particular structure, as theentire dam-crest may with the exception of the front or damming-face beof open or skeleton construction and may be built of wood, structuraliron, or other suitable maand exof the pool to permit the terial. Theside walls 5 have a general sector shape. The bottom is shown as bracedwith a skin plate 7 and the top by a plate 8; but any suitable knownform of bracing may be used. The front or damming face of the crest isin any case closed and herein shown as covered with skin plates, and itis the configuration of this face that causes the automatic operation ofthe crest under a varying head of water. This front face has one or moreinclined portions 9 and 11, which are both active faces, and preferably,but not necessarily, a dead portion 10, which is here shown as a curvedface having for center the center of shaft 4, the essential feature ofmy invention being that the damming-face has one or more active faceswith which one or more dead faces may or may not be combined asdetermined by the peculiar conditions attending the constructions of anyparticular crest. The dead face 10 may have any shape that does not tendto lift the damcrest, and in Fig. 1 the water exerts only a pressureagainst it that is transmitted to and taken up by the shaft 4. Theactive faces 9 and 11 are inclined forward, and the water exerts anupward pressure on them to rotate the crest about shaft 4. The activeface 11 is, however, not absolutely necessary if the active face 9 beproperly proportioned, and if face 11 be omitted the dead face 10 wouldbe preferably, but not necessarily, extended somewhat above the normalwater-surface h, or the automatic action may likewise be obtained by theactive face 11 combined with the dead face 10 without the assistance ofactive face 9, or such automatic action may be obtained by an activeface 9, extending from the top of fixed dam 1 to or above the normalwater-surface h, without assistance of faces 10 and 11, provided face 9be properly proportioned and properly combined with counterweight. Nearthe shaft 4 and rigidly secured to the sides of the dam are arms 12,each stifiened by a rib or T-iron 13 and carrying fixed at their upperend a box 14 or other device capable of containing suitable weights tohold the crest down under normal conditions.

The operation is as follows: The counterweight is so proportioned thatthe downward moment of the crest and counterweight combined is enoughgreater than the upward moment of the water pressure under normalwater-level h of the pool to overcome frictional resistanceand keep; thecrest resting on top of the dam 1. As soon as the water-level rises-sayto t-the upper active face 11 will be acted upon by the depth of waterbetween it and i and the active face 9 will have a greater tendency tolift by reason of the increase of head hi, so that as soon as the smalloverrnoment to overcome frictional resistance is overcome the crest willautomatically rise and allow the water to pass between its bottom andthe top of the dam 1. The amount of counterweight to be used de pendsupon the weight and downward moment of the crest. In certain conditionsthe weight of the crest and'its downward moment being sufficient or morethan sufficient to exceed the upward moment ofthe waterpressure underthe normal water-level h of the pool sufliciently to overcome frictionalresistances, the counterweight will be, as the j case maybe, eithereliminated or attached on the opposite side of pin or shaft 4 from thatshown by the drawings.

The pressure on the activeface 9 acts to raise the crest with a leverarm0 and that on the active face 11 acts to raise the crest with alever-arm 7c. 1 f

In order to prevent too great a lift or an overliftof the crest, anysuitable 'stop may be provided to limit the upward movement, and to thisend I have shown a'chain 15, 'se-' cured at one end to the masonryabutment or side wall 2 and at the other e'nd'to the crest. Where thepool is large, convenience of structure of the crest may require that'sev-' eral such dam-crests be placed side by side,

and the side wall, as 5, of such" section will act as abutment for'thefadjace'ntsection, some water, preferably, but not necessarily,

being permitted to leak past the adjacent sections. p p

The amount of water which passes'between the ends of'thecrest and theside walls or abutments is relatively very small compared with thatwhich passes below the crest. If in any particular case in practice thisleakage be unimportant, a small but sufficient'clearance may be left atthese points without passed a shaft 19. From this shaft is hung, bymeans of hangers 20, a box 21, provided, but not necessarily,

with a hinged lid capable of being locked. In the box are placed theweights for counterbalancing the crest. The

box 21 is capable of swinging about the shaft l9'when the crest rises.Secured to the top of the crest at the back and projecting toward therear are inclined arms 22, having "upwardly-bent ends 23, against whichthe counterweight-box will rest when the box swings a certain distanceto the rear. So long as the counterweight swings freely on 19 as an axisits weight acts as if it were on this axis no matter what the positionof the crest; but when in the course of the rise of the crest thecounterweight strikes the upwardly-bent ends 23 of arms122 the weightcan no longer freely swing, and the effect will be to transfer theweight from its axis of swing 19 to its own-center of gravity, and Ihave found from actual practice that such a structure is satisfactory asa stop, so that no auxiliary means, as chain 15, Fig. 1, will berequired to prevent the crest from going over the center even during theextreme flood stage, al-

though an auxiliary stop may be added as an additional safeguard.

I claim 1 A movable dam-crest having one or more active faces acted uponby the rise in levelof the water dammed,- thereby to automatically liftthe crest. I 2. A movable dam-crest having one or more active faces andone or more dead faces, said active faces acted upon bythe rise in levelof the water dammed, thereby to automatically lift the crest- 3. Amovable dam-crest having an upper and a'lower active face and a deadface between them, said active faces acted upon by the rise in level ofthe water dammed by the crest to automatically lift said crest.

4. An automatically-lifting dam-crest automatically raised by theincreased lifting pressuredue to an increase of head of the waterdammed, to permit the, excess of water to pass under the crest.

5.A movable dam-crest having an active face inclined upwardly and towardthe water dammed, to automatically lift the crest by reason of theincreased head of the dammed water, substantially as described.

6. A movable dam-crest having an active face normally below and anactive face normally above the normal water-level of the water dammedand both acted upon by the increase of head in the water dammed toautomatically lift the crest, substantially as described.

7. The combination with a dam and lateral abutments, of anautomatically-movable dam-crest mounted between the abutments, one ormore active faces on said crest acted upon by the head due to the riseabove normal of the level of the water dammed, and means to limit therise of the crest, substantially as described.

8. The combination with a dam and abutments; of a movable dam-crestmovable tween the abutments, and a substantially sector-shaped dam-crestmounted at its center of rotation on the shaft and resting on the dam,said crest having one or more active 1 faces acted upon by the rise ofthe water dammed above the normal level to automatically raise thedam-crest, and a counterweight carried by the dam-crest.

10. he combination with an automatically-movable dam-crest; of acounterweight freely suspended on the dam-crest and means 5 to limit theswing of the counterweight and i thereby automatically change theeffective point of application of the weight, substantially asdescribed.

11. The combination with a dam and lateral abutments; of anautomatically-movable crest, normallyresting on the claim, a

pair of arms extendmg upwardly from the I crest, a counterweightsuspended from the arms, and rearwardly-projecting inclined I armshaving upwardly-extending ends in the l path of swing of the weight tolimit the swing l of said weight, substantlally as described.

12. The combination with a dam and lateral abutments; of a shaft mountedbetween the abutments at about the normal waterlevel, a substantiallysector-shaped dam- 5 crest mounted at its center of rotation on theshaft, said crest having a curved dead face whose center of curvature isthat of the shaft, and an upper and lower inclined active face actedupon by the head due to the rise in 40 level of the water dammed,upwardly-extending arms secured to the sides of the crest, a shaftmounted in the upper ends of the arms,

a counterweight-box, hangers suspending the box from the second shaftand means to limit 4 5 the swing of the box, substantially as described.

13. An automatically-moving dam-crest having a damming face of a generalconvex form presented to the water dammed, means 50 to pivot the dam atabout the center of ourvature of the face, said face acted upon by theincreased head of water dammed to permit the excess of Water to passunder the crest.

In testimony that I claim the foregoing as my invention 1 have signed myname in presence of two subscribing witnesses.

\VM. R. DAVIS.

Witnesses:

H. F. KELLOGG, A. G. HAYDEN.

